Anthraquinone vat dyestuff



Patented Nov. 6," 1928.

UNITED STATES PATENT OFFICE.

WALTER MIEG, OF VOHWINKEL, GERMANY, ASSIGNOR TO GRASSELLI DYESTUFF COR-PORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

ANTHRAQUINONE VAT I)YESTUFF.

No Drawing. Original application filed January 20, 1926, Serial No. 82588, and in Germany January 21,

1925. Divided and this application filed May 24, 1927. Serial No.193,948.

This invention relates to the preparation of vat dyestuffs of theanthraquinone seriesby submitting certain anthra uinone derivatives toan aluminum chloride usion in the presence of tertiary bases and tocertain new products pre ared according to this process.

In several erman patents, as for example, 136,015, 240,080, 249,000 and262,788, the fusion of anthraquinone derivatives with aluminum chlorideis described. In these patents, the substances are heatedto temperaturesof 220 to 270 C. in admixture with a large excess of aluminum chloride(up to 5 parts by weight).

We have found that such fusion can be carried out not only with smalleramounts of aluminum chloride, as for example, with only one part byweight, but also that it can be carried out at considerably lowertemperatures if-aluminum chloride is used in the presence of tertiarybases such as pyridine, quinoline, dimethylanilim'etc. For example,anhydrousaluminum chloride is mixed with one to four times its Weight ofdry pyridine, and a very well crystallizing compound of both components,which is soluble in excess pyridine, is obtained with evolution of'heat,and then the substance that is to be fused is introduced with stirring.Then it is quickly heated to the reaction temperature which is about C.lower than in the case of the acid aluminum chloride melts. The reactionproduct is thus obtained partly in the form of a leuco-compound fromwhich it can be :5 egsily isolated by treatment with the oxygen Theprocess just described presents very important advantages over theprocesses of the patents mentioned. Besides the diminution o of theamount of aluminum chloride, the frothin which is very great in the caseof the aci melts and which makes the process diflicult, is lessened, andmost important of all, the present process yields very ure prod- 5 uctsdirectly inexcellent yields ue to the 1 lower reaction tern erature andthe presence of a base whereby t e injurious effects of freehydrochloric acid at high temperatures are avoided. lVhile for example,according to German Patent 210,080, 1.1 dianthraquinonylamine yields abrown vat dyestuif on heating to 220 C. with aluminum chloride which isconverted into a crystalline yellow dyestuif only after treatment withsodium hypochlorite at 80 C. according to the process of German Patent251,021 and with considerable loss of yield, according to Example 1 ofthe parent application, a product is obtained at C. which on contactwith the oxygen of air yields the same yellow dyestutf in quans about180 C. (Example 6) of parent applica-- tion. Flavanthrene when preparedby melting Q-aminoanthraquinone with aluminum' chloride alone, isobtained only at temperatures of 250 to 280 C. (German Patent 136,015).

The inventionis illustrated by the following example:

Example.

Ten parts by weight of 4-benzoylamine-L1 dianthraquinonylamine aresuspendedin 50 parts by weight of pyridine, 16 parts by weight ofanhydrous aluminum chloride are introduced and the mixture is heated forabout twenty minutes to C. until a homogeneous olive-brown melt results.The mixture is worked up by stirring it into dilute caustic soda whichcontains the amount of hydrosulfite neeessar to reduce the dyestuftformed, and then the reaction product is separated b blowing in air andfiltering the vat. The yestuff is obtained in good yields and isdifiicultly soluble in high boiling or ganic solvents. It yields browncolored solutions in concentrated sulfuric acid. It dyes which ischemically most likely a carbazol cotton very fast brown shades fromcold and derivative, corresponding probably to the warm vats, andcorresponds probably to the formula formula COCIHI co 0 o in:

so I C0-C6H5 Co This is a division of my application Serial No. 82,588,filed January 20, 1926. which is soluble in concentrated sulfuric acid Iclaim: with a brown color and dyes vegetable fibres As a new product tht d t ff hi h from cold or hot vats very fast brown shades. isobtainable by treating 4-benzoylamino- In testimony r f, I fliX my Signure. 1-1-dianthraquinonylamine with anhydrous aluminum chloride inpresence of pyridine, WALTER MIEG.

